Answer:
The circulatory and respiratory systems absorb oxygen from the air and transfer it to all parts of the body while absorbing carbon dioxide from the body and releasing it into the air. When a person inhales, the lungs expand and fill with fresh air.
Explanation:
Basically, humans use lot's of energy for heating, lighting, movement, and machines, that energy has come from and energy source. Some sources are renewable, and some are None-Renewable. In general as a Non-Renewable source are fossil fuels. These come from under the ground meaning that there not usable. There can be a fixed amount of coal, oil, and gas in the world and when we use this energy then its gone and there is no coming back.
-Hope this helps .
1/3 im pretty sure......................
That would be Biochemistry. as that is th study of chemical changes and processes in living organisms
